Does it just close with feel? or does it swallow the guage? I'd send it back if it was new. There was a thread from a year or two ago or so where someone was saying some manufacturer was using different specs on 5.45 bolts. Can't remember who it was though. Kreiger owns Criterian or something to that effect. Give then a shout Criterion Barrels, Inc.

It closes with a little resistance..but very little.. the problem is I got the barrel from a guy on a board at a good deal it was new...not used..and I got the bolt from Model 1 sales at not a good deal..so I really can't return anything..and I can't play musical bolts with the 5.45 as the head dia and firing pins are different.. I'm using AK-builders gauges.. I guess I have to run it and see if it works.. I wonder if others have upper that close on the no go gauges also.. B2B

Adjusting the headspace on a AR rifle requires the barrel extension to be removed and a thread set back, and it really cant be done once the gas port is drilled because it will no longer time up top dead center... it requires a lot of tools and expertise... I don't have either and unless it is short chambered and a reamer could be run into it, but it's not it is long.. It may be a bolt issue..but I really can't test it on a round using a 556 bolt because of the head dia difference.. If it is a bolt issue, I may be able to get model 1 sales to swap me a different bolt but that is going to be a majoy PITA and I already had to have them send me a firimg pin that was all F't up.. I'll just run it and see if it functions but I think I may be FKd another issue with excessive hadspace is the extractor doesn't grab the rim of the case.. I tried a case and it didn't grab the loaded wolf round.. that is why I checked HS.. I'll contact Kreger.. and see what's the deal.. B2B

I almost wonder if they sent you the wrong bolt. I recently opened up a 556 bolt to .398" for a 9mm build. The 9mm bolts I measured had a bolt face diameter between .397" to .405" with the 5.45x39 bolt being towards the lower end of that spread. I was going to just use the 5.45 bolt until I found used 556 bolts cheap. Whats the bolt face diameter of yours?

bolt is .396 and it is a citadel barrel not a kreger.. so not in the same league.. I think it will run in the NO go just may not be as accurate or may not work well with brass cases... like I pan on using.. B2B

i just wrnt threw somthin very similar 7,62x25 tok AR15 I ask the guy building my barrel and setting my headspace if he needed my bolt his reply was "Not unless it is an alexander arms bolt. They are the only ones that cut the bolt .010 deeper.what brand is yours?